New findings may help women struggling with fertility

22 March, 2016

New research shows that boosting egg health and development could improve the chances of women getting pregnant through IVF.

A research paper published in the journal, Scientific Reports on March 18, shows that improving the quality of an egg during fertilisation results in increased chances of achieving fertilisation and embryo development. The research was led by the Head of the Centre for Genetic Diseases, at Hudson Institute of Medical Research in Melbourne, Professor Justin St. John, Ph.D.

Using a large animal model, where egg and embryo development are very similar to the human, the study took mitochondrial DNA from one female’s egg and supplemented it into another of her eggs with low mitochondrial DNA copy number (poor egg quality or health) at the same time as the sperm fertilised the egg. This resulted in healthy embryos developing from the supplementation process.

“It’s becoming clearer that mitochondrial DNA has a bigger role to play in fertilisation outcome and embryo development,” said Professor St. John.

A healthy egg normally contains more than 150,000 copies of mitochondrial DNA, which help to provide the ‘energy’ an egg needs to develop during and after fertilisation.

“Failure to have enough mitochondrial DNA can result in fertilisation failure, embryo arrest and other genetic disorders.”

A number of women undergoing IVF have insufficient mitochondrial DNA (less than 50,000 copies), which often results in their eggs failing to either fertilise or develop into embryos. A woman’s age, environment (toxins, smoking) and medical issues are some of the factors impacting egg health.

Professor St. John’s research suggests that supplementing a woman’s egg with mitochondria from an autologous source such as another of her eggs during in vitro fertilisation (IVF) could significantly improve fertilisation and development into an embryo. However, this process could depend on egg availability. Alternative sources such as immature egg cells can be used as the autologous source of mitochondria.

The discovery shows that the health of an egg depends, in part, on the number of mitochondrial DNA copies that exist in an egg cell.

The research was undertaken by Professor St. John in conjunction with first authors Dr Gael Cagnone and Te-Sha Tsai (PhD student) and collaborators Dr Yogeshwar Makanji, Pamela Matthews, Jodee Gould and Dr Matthew McKenzie (all from Hudson Institute of Medical Research) and Dr Kirstin Elgass (Monash Micro Imaging Microscopy Specialist).

This study was sponsored by OvaScience, a global fertility company dedicated to improving treatment options for women around the world. The results support the mechanism of action for OvaScience’s AUGMENTSM fertility treatment, which is designed to improve the health of a woman’s existing eggs when used in conjunction with IVF. The AUGMENT treatment uses energy-producing mitochondria from a woman’s own immature egg cells found in the protective lining of the ovaries to supplement the existing mitochondria in her egg.

Read the full publication here: http://www.nature.com/articles/srep23229